Blown Lower Intake Gasket....CRAP!!!!!

[BlazerLT]

Guys, it has happened. I don't know how long this has been occuring, but I went out to the truck to check the oil and the oil was completely fine, clear and I wouldn't have expected anything out of the ordinary.

Until I too a look at what was inside my PCV catch can that is:



I thought, what the hell, it is probably just some water vapour frozen in the caught material seeing it was -15c when I was checking this.

I brought it inside and stuck the vial in some hot water to see if I could get the water to separate. Low and behold a lot of the material was indeed water but there was something else too.



My heart just sank, this could have been going on for how long? Years? Months? Who knows.....

Looks like the lower intake gasket wil have to be changed and that is what is probably causing my weird idle sometimes in the hot summer days.

[Gabe25]

Tuff break, Maybe you can get Girlbear to give you a hand. She no longer a rookie when it comes to replacing the lower gaskets. Good luck. Does this mean that you'll have to put off your trip to Hawaii a few more years...

[BlazerBoyLT98]

Sorry to hear that bro. WHat are you going to do? Do you think you will do the work or a dealer?

[BlazerLT]

I will do the work.

The gasket kit only costs 47 bucks and that includes the lower intake and the upper intake gasket along with the distributor gasket.

I am so bummed right now.

I don't know for sure if it is the intake or the head gasket.

Anyone know for sure how to tell?

[BlazerBoyLT98]

If it was the head gasket wouldn't you be losing a lot more oil? I had a jeep cherokee with over 200K on it and when the head gasket went I was losing a quart of oil every few days until I replaced it.

[Gabe25]

Originally Posted by BlazerLT

I will do the work.

The gasket kit only costs 47 bucks and that includes the lower intake and the upper intake gasket along with the distributor gasket.

I am so bummed right now.

I don't know for sure if it is the intake or the head gasket.

Anyone know for sure how to tell?

LT, Do a compression test and watch for leak down in each cylinder. If there all about the same. Your head gasket should be OK.

[70Nova05]

If it helps, I have a 93 S-10 Blazer that blew an intake gasket and acted exactly the same way. It is a longer job than you might first think, so put away about 3-4 hours to do this job. Head gaskets you can typically either hear or see signs of leakage, such as an air sound from loss of compression, or water in your oil. The intake leaking is a massive vacuum leak and will cause a lot of performance loss.

[TonyMazz]

Originally Posted by BlazerLT

Guys, it has happened. I don't know how long this has been occuring, but I went out to the truck to check the oil and the oil was completely fine, clear and I wouldn't have expected anything out of the ordinary.

Until I too a look at what was inside my PCV catch can that is:



I thought, what the hell, it is probably just some water vapour frozen in the caught material seeing it was -15c when I was checking this.

I brought it inside and stuck the vial in some hot water to see if I could get the water to separate. Low and behold a lot of the material was indeed water but there was something else too.




My heart just sank, this could have been going on for how long? Years? Months? Who knows.....

Looks like the lower intake gasket wil have to be changed and that is what is probably causing my weird idle sometimes in the hot summer days.

That's too bad ! Your truck has how many miles on it ? 150K or so right ? I suppose that is about right for an intake gasket life.

I was told once that these motors last along time, but eventually eat gaskets, i.e. head, intake etc....

I suspect that while you are in there, you can check for other issues, and get a sense by looking down the valley a the cam, etc how things are doing lubrication wise....take pictures....

[TonyMazz]

I don't know if a reference to what would have to be done on a 99 4.3L would be of any help, but here is the basic sequence....If it's any consolation AllData says...

Disconnect the battery negative cable. Refer to Battery Replacement in Starting and Charging.

Remove the air cleaner outlet duct from the throttle body.

Remove the air cleaner assembly.

Drain the cooling system.

Remove the radiator inlet hose at the water outlet.

Remove the heater hose from the intake manifold.

Remove the water pump inlet hose form the intake manifold.

Disconnect the accelerator control cable from the throttle shaft and the accelerator cable bracket.

Disconnect the cruise control cable, if equipped from the throttle shaft and the accelerator cable bracket.

Remove the accelerator cable bracket from the throttle body and the intake manifold

Remove the accelerator and the cruise control cable bracket from the throttle bracket. Leave the accelerator and cruise control cables and the wiring harness on the bracket

Remove the following electrical connectors:
The fuel meter body assembly
The EVAP canister purge solenoid valve
The idle air control (IAC) motor
The throttle position (TP) sensor
The A/C compressor high pressure switch, if equipped
The A/C clutch switch, if equipped
The exhaust gas recirculation (EGR) valve
The engine coolant temperature (ECT) sensor
The ignition coil
The ignition control module (ICM)


Remove the engine wiring harness from the retainers.

Move the engine wiring harness aside.

Remove the distributor.

Remove the Exhaust Gas Recirculation (EGR) valve inlet pipe from the intake and exhaust manifold.

Disconnect the fuel supply and return pipes at the rear of the intake manifold.

Disconnect the vacuum hose from the intake manifold, if equipped with A/C.

Disconnect the vacuum brake booster hose

Disconnect the PCV hose assembly from the intake manifold and the valve rocker arm cover.

Perform the following in order to remove the left front bolt for the intake manifold:

22.1. Remove the drive belt. Refer to Drive Belt Replacement.
22.2. Loosen the nut for the power steering pump rear bracket at the side of the engine.
22.3. Remove the secondary Air Injection (AIR) reactor pipe bracket nut from the power steering pump rear bracket front stud, if equipped.
22.4. Remove the nut for the power steering pump rear bracket at the front of the engine.
22.5. Remove the bolts and the nut for the power steering pump mounting bracket.
22.6. Leave the A/C compressor, if equipped, and the power steering pump on the power steering pump mounting bracket.
22.7. Slide the power steering pump bracket forward to access the bolt at the front of the intake manifold.

Remove the EVAP canister purge solenoid valve

Remove the lower intake manifold

Clean all sealing surfaces

Finally --- Notice: Proper lower intake manifold fastener tightening sequence and torque is critical. Always follow the tightening sequence, and torque the intake manifold bolts using the 3 step method. Failing to do so may distort the crankshaft bearing bore alignment and cause damage to the crankshaft bearings.

[Cailen]

Crappy deal bro... like Gabe said you want your lowest and highest compression cylinders to be within 10% of each other. Remember to crank like 6x when checking, and record the numbers on the first and last crank.

If you have any questions or concerns lemme know... I took a LOT of pictures when I was doing my lower gasket. Let me know how that EGR port of yours looks too. And remember.. you want that gasket surface as clean as the virgin Mary's panties. Oh.. and weatherstrip adhesive is way better around the coolant ports than RTV.

Looks like your catch can mod is useful after all

Good luck buddy!

[BlazerLT]

Tony,

I thank you so much for your information.

I just went to the shop and they said they would charge me 3-4 hours for it and I can buy the parts, oil and coolant to bring in.

So the job is not going to be that expecnsive and seeing it is -15c here right now, I can't do this in the parking lot.

This has gotten worse, I dumped and cleaned the catch can, drive for 50 miles and the catch was 1/4 filled with yellow milky sludge.

The oil itself is perfect and is not milky at all so for sure I can't blame the headgasket. Plus the engine is running perfectly and there is no thick plumes of white smoke coming out the back even on hard acceleration.

Thank god for this PCV catch can. It just paid for itself right there. I don't know how soon I am going to fix it. The small amount of coolant you saw there took over 1000 miles to collect and seeing it is collecting there rather than the oil I am glad.

This catch can is a blessing.

[OverBoardProject]

I like that catch can mod LT, I'll have to do that.

I can't say anythig else, except I hope that you have a heated shop to use.

[BlazerLT]

Originally Posted by OverBoardProject

I like that catch can mod LT, I'll have to do that.

I can't say anythig else, except I hope that you have a heated shop to use.

Nah, I am having a shop do it for me. It is not that I can't do it, it is that it is too cold to do it here. -15c here right now and a winter storm really.

The kit is only $50 and includes the lower, upper and distributor gasket.

I will supply the oil and coolant.

They said 3-4 hours labor and they charge CDN$70 an hour.

I would rather pay than doing this in this cold snowy weather.

[OverBoardProject]

Don't balame you. I sometimes get a mechanic friend to do my work when I just don't want to do the job.

He's starting to heat his shop and make me work on my own vehicles in there when it's cold out.

I'm probably at the same stage as you now. Just maintance, and the odd job that needs doing.
plus 1 or 2 small mods most months

[BlazerLT]

Yea, and once this is fixed I think I will be honestly laughing.